libvpx-vp9 rejects cpu-used and speed values [-16, -9] and [9, 16]

Description

libvpx-vp9 rejects cpu-used values from -16 to -9 and 9 to 16 (inclusive), even though the included help claims it can accept it. However, libvpx (VP8 only) accepts the mentioned values. This means that VP9 encoding will only use half of the CPU, whereas VP8 encoding can use all of it.

Change History (6)

Contrary to its name, cpu-used doesn't actually control how much overall CPU is being used, it controls the quality of the encode, and both vp8 and vp9 could have different limits. The vp9 encoder doesn't scale well with high cpu core counts, so 50% already seems pretty good.